1. Field of Invention
The present invention relates to an image input apparatus that makes digital data from images on image bearing media such as photographic film.
2. Description of Related Art
Many types of image processing methods have become easier to perform by converting film images photographed by cameras into electronic data.
There is a known film scanner (Japanese Laid-Open Patent No. 5-75922) that serves as an image input apparatus for converting film images into electronic data.
FIG. 11 is a structural drawing showing this film scanner. As shown in FIG. 11, a film scanner 41 comprises a film feeding reel 43, a film loading component 44, a take-up reel 45, an imaging optical system 46, a two-dimensional image sensor 47, an image signal processing circuit 48, and video monitor 49. The imaging optical system 46 comprises an illumination unit 46a and an imaging lens unit 46b.
Photographic film 42 is loaded into the film loading component 44. The film feeding reel 43 feeds the photographic film 42. The fed photographic film 42 is taken up by take-up reel 45. The part from the film feeding reel 43 to the take-up reel 45 constitutes the film feeding system.
The two-dimensional image sensor 47 comprises a CCD image sensor. The image signal processing circuit 48 processes the image signals read by the two-dimensional image sensor 47 and video monitor 49 displays the images processed by image signal processing circuit 48.
In the structure described above, one frame of the photographic film 42 is positioned in a specified position of the imaging optical system 46 by being taken up by the take-up reel 45. In that condition, the transmitted images of the photographic film 42 illuminated by the illumination unit 46a are read by the two-dimensional image sensor 47.
Image reading is performed by projecting the transmitted images of the photographic film 42 onto light-receiving areas of the two-dimensional image sensor 47 through the imaging lens unit 46b. These read in images are processed by the image signal processing circuit 48, and then are displayed on the video monitor 49.
Due to the above construction, dust and other foreign particles tend to attach to the image reading areas of the photographic film.
As shown in FIG. 11, the upper surface of the photographic film 42 is in an open condition in the area below the imaging lens unit 46b. Therefore, foreign particles from the atmosphere tend to intrude. Also, when foreign particles exist on the image reading areas of the photographic film 42, the foreign particles end up being copied into the read in images.